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Two Level Word Decode with Layout Advantages

IP.com Disclosure Number: IPCOM000076944D
Original Publication Date: 1972-May-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Cassani, JC: AUTHOR

Abstract

This is a decoder circuit using the decoder inputs to achieve restore, thereby eliminating an input to the chip while also eliminating two metal conductors in the decode area to reduce the time constant problem, by charging the internal node to a higher voltage than the external node.

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Two Level Word Decode with Layout Advantages

This is a decoder circuit using the decoder inputs to achieve restore, thereby eliminating an input to the chip while also eliminating two metal conductors in the decode area to reduce the time constant problem, by charging the internal node to a higher voltage than the external node.

The decoder circuit of Fig. 1 is reproduced many times in the memory array. Each circuit comprises four field-effect transistors (FET's) 10, 11, 12 and 13 coupled in pairs parallel to an external node 15, which is connected to the decode input devices 31, 32 and 33. Four FET devices 16, 17, 18 and 19 are also coupled in pairs in series with FET's 10, 11, 12 and 13 to establish internal node lines 20, 21, 22 snd 23, which are in turn coupled to the gates of output FET's 27, 28, 29 and 30. These, in turn, are coupled to word lines 34, 35, 36 and 37, respectively. The drains of FET's 27 and 30 are connected to a voltage input 40, while the drains of FET's 28 and 29 are connected to a voltage 48. The gates of FET's 16, 17, 12 and 13 are connected to a voltage input 41 and the gates of FET's 18, 19, 10 and 11 are connected to a voltage input 42.

Application of positive voltage pulses A & B shown in Fig. 2 to inputs 41 and 42 precharge the lines 20, 21, 22 and 23 to a voltage higher than node .15. The pulse A may be applied to either input 41 or input 42, while the pulse B is being applied to the other input.

For purposes of example we will ass...